How to change the Monitor brightness on Linux?

Question

How do I programmatically change the monitor brightness on Linux?

I\'m using SLES 11.

Answer 1

edit /etc/default/grub file and add

“pcie_aspm=force acpi_backlight=vendor” after

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”

after the changes, the whole line will look like this

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash pcie_aspm=force acpi_backlight=vendor”

Chirag Singh

Answer 2

If you have multiple displays and php installed, put this in

/usr/bin/brightness

#!/usr/bin/php
<?
$br=(double)$argv[1];
if(!$br||$br>1) die("enter brightness lvl 0.1 - 1");
preg_match_all('!^(\S+)!m',`xrandr --current | grep ' connected'`,$m);
foreach($m[1] as $display){
        echo `xrandr --output $display --brightness $br`."\n";
}

than call brightness .7

Answer 3

You can try using xbacklight.

xbacklight -set 100

Answer 4

command for this:

xgamma -gamma 0.7

Answer 5

For me it works perfectly with xbacklight. If you for example wish to set up a key binding, you can use

bindsym $SUPER+Shift+plus   exec  xbacklight -inc 10
bindsym $SUPER+Shift+minus  exec  xbacklight -dec 10

in your window managers config (I use i3) to regulate your screen's brightness level.

I wouldn't recommend xrandr for this since it doesn't stop at 100% brightness automatically.

Answer 6

On my machine I run the following as root:

echo -n 10 > /sys/devices/virtual/backlight/acpi_video0/brightness